Hollow panel



March 16, 1937. E. c. LOETSCHER HOLLOW PANEL INVENTOR fM/L IC. 05m c1152,

Filed March 28, 1935 meme Mar. 16, 1931 UNITED STATES PATENT OFFICE v Maxwell... Application M 28, 1935, N0. 13,518 3 Claims. (CI- 20-41) The object of this invention is to produce a flat panel, such as a door, table or desk top, or l in fact any flat surfaced panel, employing a lattice-work core and thereby avoiding the tendency to warping and twisting, particularly in products of large size.

A further object of this invention is to make the assembling of such a panel more practical from a manufacturing standpoint, and to avoid 1o complicated machining.

With these and other objects in' view, reference will be had to the accompanying drawing, forming a part of this invention and in which:

Fig. 1 is an assembly view during a stage in the manufacture of a. panel foundation, V

Fig. 2 is a top plan view of a fragment of assembled foundation,

Fig. 3 is a view in end elevation of a fragment of the foundation,

Fig. 4 isa transverse sectional view taken on lined-l of Fig. 2, with veneers juxtaposed,

Fig. 5 is a transverse sectional view taken on line 5-5 of Fig. 2 with the veneers applied,

Fig. 6 is longitudinal sectional view taken on line 6-6 of Fig. 2 with veneers applied,

} Fig. 7 is a perspective view of a fragment of a transverse lattice strip,

Fig. 8 is a top plan view of .a fragment of a finished product,

Fig. 9 is a detail view, Fig. 10 is a view similar to Fig. 6 of a modified form,

Fig. 11 is a view similar to Fig. '7 of a modified form, and

Fig. 12 is a perspective view of a modified longitudinal lattice strip.

In the drawing, reference numeral I designates the top and bottom rails and 2 the stiles of the outer or surrounding frame of a door or other panel. The stiles are provided in their inner faces with coextensive longitudinal grooves 3 located centrally between their upper and lower faces, and the rails are provided in their inner faces with longitudinal ribs 4, also located centrally between their upper and lower faces. The ribs extend the full length of the rails and join with tenons 5 formed in the ends of the rails.

Blocks 6, lmown in the art as lock-blocks since they take the lock and handle hardware, are formed along one longitudinal edge with a rib I and along the opposite edge with a groove 8. Longitudinal grooves 9 are also formed in the upper and lower faces of the lock-block.

The aforementioned parts virtually constitute the surrounding frame for latticework which to a stile ifonly one lock-block is employed. and

comprises and longitudinal strips II and ii respectively. 'l'hetransversestripsmay becutsquareattheirendstoabutthesiilsi,

but are preferably provided with tenons I! to fit thestiiegroovesS. Mostofthes strips Ill extend from one stile to the other, except where lock-blocks are employed and in that case'they extend from one lock-block to another if two lock-blocks are used, or from the lock-block these shorter strips also preferably havetenons i2 tofltintothegroovesofthe lock-blocks or stiles.

Notches ll are provldedintheupperandlower edges of the strips" to receive the longitudinal siu'lps II which seat upon l5 and occupythesameverticalplane,asdothe notches ll. The notches ll terminateinsmaller ventilation notches I6 which extend beyond and are located between the shoulders l5.

Thedistance from the outeredgeofastileor rail to its groove orribisthesameasthatfrom the outeredgeof thestripstotheir shoulders l5 or tenons l2, and the same as the vertical dimension A of the longitudinal strips.

The parts are assembled by the transverse strips III on edgein notches l'l formedin side marginal ribs "of a orjig IS, with the ends of the strips ll beyoml the sides of the gage or jig. An adhesive, suchasordinary or caseinglue,is applied onthe tenons l2 and the stiles 2 are moved into ment with the strip ends. the tenons of the longer strips In entering the grooves 3 of the stiles and those of the shorter strips ll entering 35 the grooves 8 of the lock-blocks which previously had been placed in position for their glued ribs Ito enterthestilegroovesl. Therails l are neirt placed between the stiles 2, with an adhesive applied to their ends and their tenons 5 entered into the stile grooves 3.

The strips II are then insertededgeways into the upper notches l4, which now are all aligned due to the aligning action of the stiles in bringing the ends of the strips lil into proper position. Previous to the insertion of the strips l I, glue is applied to each at the points where they intersect the strips ill and bear upon the ribs 4. This glue needs be applied only on the bottom edges of the strips II, since asinall amount of glue at this point will hold the strips firmly in position,

though as a matter of fact the glue will distribute itself more or less onto the sides of the notches M as the strips enter the same.

The assembly is then turned over, the gage or 55 jigremoved.andthestrips H forthatside of the panel similarly applied.

After the glue has set, the whole assembly is preferably sanded to uniform thickness and to 5 remove all projections.

After sanding, the assembly is preferably run throughagluemachine,thoughthe workmaybedonebyhand,to place glue upon theedgesoftherailsandsiilesandalledgesof the lattice-work. A three ply wood veneer maythenbe appliedandplacedinapressuntil the glue hasset. after which the product is removed from the press and sanded.

In the modified form of Figs. 10 and 11, the

15 longitudinal strips II have depending portions 2|, and these portions of superposed strips come into contact with each other, and maybe glued together if desired. This construction requires notching of the longitudinal strips at 2!, but

menablesthecellstobelargerthaninthe first form,sincethestrips llwill amply support the face veneers 2| against press pressure when applylngtheveneers. Wlththefirstform,thecells must be relatively small to prevent the strips from under press pressure. In the second form, the veneers 20 are single ply, the nature of the wood veneer used not forming an essential part of the invention.

Ventilation is aiforded between the cells through the spaces between the longitudinal strips II in the preferred form, and through the notches 22 in the second form, the notches 22 being wider than the thickness of the transverse strips In. Since superposed strips H engage each other by their portions ii in the second form,

the strips ll need not rest upon shoulders I! of the transverse strips as in the first form and may be notched deeper at 22 to clearthe shoulders i5 and provide an air passage between the bottom 22 of the notch 22 and the shoulders l5, or in lieu thereof, the distance A may be maintained in strips II and the notches ll of strips ll cut deeper, that is, to a depth corresponding to the base line of the notches It of strips ill to 45 provide ventilation space. While the second form has structural advantages over the first form, notching of the strips I l' entail additional manufactm-ing costs.

Due to imperfections in machine work, there are usually variations in the thickness of the strips I l and I l' or evenin the notches I, whereby spaces will occur betweenthe walls of the notches I4 and strips II and I l 'sufilcient for ventilation without the employment of the additional vents I i, however when the machining is more accurate, provision must be made as previously outlined for the passage of air between the bottoms of the strips II and l l and where they intersect the strips ll.

Usually, the notches M are cut 1/64" wider than the thickness of the strips H, II so as to make entry of the strips II, II into the notches ll easier. The stated inaccuracies along with the warping or twisting of the strips II and II will cause them to assume various positions within the notches, binding sometimes against one wall and sometimes against another wall of the notches l4, thereby imparting considerable bracing action even though the strips II and H may be loosely fitted into the notches II.

It will be noted that the lock-blocks are located and confined'by the various strips and that the ones that are embedded in the lock-blocks in no manner impair the utility of such blocks or intersplit in any direction.

may be used for the veneer, and is highly desirable since it has equal strength in all directions and is not open to the objection that it will It permits a thinner veneer to be used and may be used single ply and will readily receive a paint or even paper thin natural wood veneer.

Even the lattice strips may be made of the same synthetic lumber and will have a greater degree of accuracy as to thickness since they will all be out from sheets of accurate and uniform thickness. 7

The lattice strips II and H need not be continuous, but may be sectional, the sections preferably making joint at points where they intersect the strips IO though there is no great objection to the joints occurring between said strips 10, since provision is made in the various forms for amply supporting the upper and lower strips regardless of where their joints may occur.

The facings 20 and 20' may be omitted without destroying the utility of the foundation for certain purposes, such as grille doors, but the construction is designed particularly to receive the facings.

What is claimed is:

1. A structural unit, comprising an outer frame of jointed members, a first series of parallel strips located'between opposite members of the frame and parallel therewith, said strips having spaced notches each with substantially parallel edges provided in their front and rear edges and of a depth less than half the depth of said strips, 9. second and a third series of parallel strips located between other opposite members of the frame and parallel therewith, the strips of the second series being-set into and adhesively secured in the notches in the front edges of the first series, the strips of the third series being. set into and adhesively secured in the notches in the rear edges of the first series, corresponding strips of the second and third series abutting each other at points between the strips of the first series, the front and rear edges of allthe strips being flush respectively, and panels secured to the front and rear edges of the various 'strips and to corresponding edges ofthe outer frame.

2. A structural unit, comprising an outer frame of jointed; members, 'a first series of parallel strips located between opposite members of the frame and parallel therewith, said strips having spaced notches each with substantially parallel edges provided in their front and rear edges and of a depth less than half the depth of said strips, a second and a third series of parallel strips located between other opposite members of the frame and parallel therewith, the strips of the second series being set into and adhesively secured in the notches in the front edges of the first series, the strips of the third series being set into and adhesively secured in the notches in the rear edges of the first.serles, the width of the notches in the strips of the first series being greater than the thickness of the strips received therein permitting easy insertion of said strips if warped into said notches, corresponding strips of the second and third series abutting each other at points between the strips of the first series, the strips of the second and third series being adhesively secured together, the front and rear edges of all the strips being flush respectively, and panels adhesively secured to the front and rear edges of the various strips and to the corresponding edges of the outer frame.

3. A structural unit, comprising an outer frame of jointed members, a first series of parallel strips located between opposite members of the frame and parallel therewith, said strips having spaced notches each with substantially parallel edges provided in their front and rear edges and of a depth less than half the depth of said strips, 3. second and a third series of parallel strips located between other opposite members of the frame and parallel therewith, the strips of the second series being set into and adhesively secured in the notches in the front edges of the first series, the strips of the'third series being set into and adhesively secured in the notches in the rear edges of the first series, corresponding strips of the second and third series having their inner edges abutting each other at points between the strips of the first series and adhesively secured together, certain strips of the first series being shorter than others of the same series, a lockbiock secured to one of the members of the outer frame and extending longitudinally thereof and being located between said member and the ends of the shorter strips'of the first series and'being also provided with longitudinal grooves, certain of the strips which are laid into the notches of the strips of the first series continuing through the grooves of the lock-block and adhesively seured therein, the front and rear edges of strips of all the series and the front and rear faces of the lock-block being flush respectively, and panels secured to the front and rear edges of the various strips and front and rear faces of the lock-block and to corresponding edges of the outer frame.

EMIL C. LOE1SCHER. 

